--When were the soldiers sent to the earthquake-stricken area? -- _______ the earthquake broke out.
Many of them turned a deaf ear to his advice, _______ they knew it to be valuable.
—Look, where are you going!—Sorry, I _______.
The relics______ the 12th century is of great value to study the life and settlement of the local people.
The headmaster called on us to ______old toys to the homeless children.
The head teacher will punish ________hasn’t finished the homework.